Barrett食道腺癌LSBE全周性病変の治療方針UPDATE

Update of Treatment Strategy for Circumferential Barrett's Esophageal Adenocarcinoma Derived from Long-Segment Barrett's Esophagus

要旨●表在型全周性病変の内視鏡治療においては，術後狭窄の問題を解決することが重要である．内視鏡治療の適応を判断する際には，深達度だけでなく周在性も重要な要素である．LSBE由来のBarrett食道腺癌（表在型）の全周性病変に対しては，長軸径5cmまでは全周ESDを，長軸径5cmを超える場合にはstepwise ESDを実施している．全周ESDにおいては，糸付きクリップ法やトンネル法を用いてトラクションをかけながら粘膜下層剝離を行うと，効率的に切除が可能である．また，術後狭窄予防のためにトリアムシノロンアセトニド局注などの施策も併用している．狭窄予防の他の方法として，stepwise ESDがある．初回のESDでは，半周から3/4周程度の範囲を切除し，瘢痕化を確認した後に残存するBarrett粘膜を追加のESDにて切除する．最深部の切除と深達度の確認を行い，T1a病変であればstepwise ESDを，T1b病変であれば外科切除を選択する．1回目のESD後，潰瘍底の上皮化した段階で2回目のESDを実施する．粘膜切開時には強い線維化が認められるため高度な技術を要するが，粘膜下層剝離時には線維化は少なく，通常のESDと同様の操作が可能である．

　The issue of post-procedural stricture should be addressed in the endoscopic treatment of superficial circumferential esophageal lesions. The depth of invasion and circumferential extent are critical factors when determining the indications for endoscopic treatment. For circumferential lesions of superficial Barrett's esophageal adenocarcinoma derived from long-segment Barrett's esophagus, complete circumferential ESD is performed for lesions measuring up to 5cm, whereas a stepwise ESD approach is employed for >5-cm lesions.

　In complete circumferential ESD, traction methods, including the clip-with-line technique or tunnel method, facilitate submucosal dissection, enabling efficient resection. Furthermore, measures, including triamcinolone injections, are used in combination to prevent post-procedural stricture.

　The stepwise ESD approach represents another method for stricture prevention. In the initial ESD, approximately 50%-75% of the circumference is resected, and following confirming scar formation, the remaining Barrett's mucosa is further resected with additional ESD. The deepest part of the lesion is resected, and the invasion depth is assessed ; a stepwise ESD is performed for T1a lesions, whereas surgical resection is employed for T1b lesions. Following the first ESD, a second ESD is performed once the ulcer bed has epithelialized. As extensive fibrosis is observed during mucosal incision, advanced techniques are required ; however, fibrosis is minimal during submucosal dissection, necessitating procedures similar to standard ESD.